Nether Portal Calculator
Dividing by 8 is the easy half. The half that goes wrong is a negative coordinate: -889 divided by 8 is -111.125, which is block -112 if you round down the way a position becomes a block in the game, and -111 if you round to the nearest block or toward zero. This page prints the unrounded value next to the block it chose, names the rounding it used and leaves the choice to you. Y is carried straight across in both directions and never divided, because the 8 to 1 ratio is horizontal only. Type Overworld 1432, 68, -889 and the Nether target is 179, 68, -112, with the exact -111.125 in plain sight; send that Nether pair back the other way and it lands on 1432, -896 rather than -889, which is the remainder the rounding threw away. What you get is a coordinate to build at: whether two portals link depends on what is already standing nearby, and the page says so rather than implying otherwise.
overworld X 1432 Y 68 Z -889 exact X 179 Z -111.125 nether X 179 Y 68 Z -112 Y is carried across, never divided
- Nether X
- 179
- Nether Y
- 68
- Nether Z
- -112
- Rounding
- Down
- One block in the Nether covers 8 in the Overworld, so X and Z are divided by 8.
- Rounded down: -111.125 becomes -112.
- Y 68 is carried across unchanged: the 8 to 1 ratio is horizontal only.
- This is a coordinate to build at. Whether the game links it to a portal that already stands nearby, instead of the one you build, depends on what is there.
The coordinates you are holding
Read them off the debug screen: F3 in Java Edition, or Show Coordinates in the Bedrock world settings. Up to five decimal places are kept, so a position pastes in as readily as a block.
How to round
Always toward the lower block, so -111.125 becomes -112. This is how the game itself turns a position into a block.
Worked both ways
The same three lines the arithmetic above produces, run through the very same functions.
Common questions
- How do I work out Nether coordinates from Overworld ones?
- Divide X and Z by 8 and leave Y exactly as it is. Overworld 800, 63, -160 becomes Nether 100, 63, -20, and because both of those divide evenly there is no rounding to argue about. Going the other way you multiply X and Z by 8: Nether 179, 68, -112 is Overworld 1432, 68, -896. The page does both directions from the same control, and the stage shows the division before the rounding so you can see where a value fell.
- Does Y get divided by 8 as well?
- No. The 8 to 1 ratio applies to X and Z only, so a Y of 68 in the Overworld is a Y of 68 in the Nether and back again. That is why Y sits on its own line here and why the stage repeats that it is carried across, never divided. The heights do not line up forever, though: the Nether is only 128 blocks tall, with bedrock at 0 and a bedrock roof at 127, so if you type a Y above 127 the page says there is no Nether height to match it rather than quietly converting it.
- Which way should a negative coordinate be rounded?
- Down, in most cases, which is why it is the default. -889 divided by 8 is -111.125, and rounding down gives block -112, the same direction a position takes when it becomes a block coordinate. Round to the nearest block instead and you get -111, because -111.125 is closer to -111 than to -112; round toward zero and you also get -111. All three are on the page because all three are asked for, and the exact -111.125 is printed beside whichever you pick so the choice is visible rather than buried.
- Why did my portal link to a portal that was already there?
- Because the game looks for an existing portal near the target before it builds a new one, and if something suitable is already standing it uses that instead. This page does not model that search and does not claim to: it converts coordinates, so what you get is the spot to build at. If an old portal keeps stealing the connection, the usual fixes are to break it or to move one of the two portals further from the other, and then convert again.
- Why does converting back not give me the number I started with?
- Because dividing by 8 usually leaves a remainder, and rounding throws it away. Overworld -889 becomes Nether -112, and -112 multiplied by 8 is -896, seven blocks from where you began. Nothing is wrong with the arithmetic: -896 is simply the Overworld coordinate that the Nether block -112 covers the start of. X behaves differently in the same example, 1432 to 179 and back to 1432, because 1432 divides by 8 exactly. The exact column is there so you can see which of the two you are dealing with.
- Can I paste the numbers straight from the debug screen?
- Yes. Press F3 in Java Edition, or turn on Show Coordinates in the Bedrock world settings, and type what you see. Up to five decimal places are kept and the division stays exact: 1432.531 divided by 8 is 179.066375 on the page, digit for digit, not a rounded approximation of it. The Copy button gives the three target numbers separated by spaces, which is the order a teleport command wants them in.
- Does this work for Bedrock Edition, and what about the End?
- Both editions use the same 8 to 1 ratio for the Nether, and that is the ratio this page applies. The End is a different matter: its coordinates run 1 to 1 with the Overworld, so there is nothing to convert. The page is arithmetic on the three numbers you type, so it does not care which edition, version or world you are in, and it reads nothing about what you have built.
Exact arithmetic at the 8 to 1 ratio, with the unrounded value shown beside the rounded one and Y carried across rather than divided. It gives you a coordinate to build at; whether two portals link also depends on what is already built nearby.